In the prior art, underrun protection systems for the rear of utility vehicles are known in very different embodiments. In the event of a road traffic accident, rear underrun protection systems are generally intended to prevent smaller vehicles (for example passenger motor vehicles, two-wheeled vehicles, etc.) from travelling under the utility vehicle from the rear, whereby there is a high risk for the occupants of the smaller vehicles of being injured or even killed. Rear underrun protection systems have to satisfy legal requirements (for example ECE R58). FIG. 6 shows a view from the rear of a rear underrun protection system known from the prior art, with a bending moment profile Mz which results from a horizontal load from the rear (for example an impact of another motor vehicle) at the testing point P1. The rear underrun protection system comprises a crossmember 2′ and two support arms 3′ for supporting the crossmember 2′ and for mounting onto the utility vehicle. A drawback here is, in particular, the high bending moment load Mz at the transition between the crossmember 2′ and the support arm 3′.